Field of the Invention
The present invention relates to image processing apparatuses, methods for controlling the image processing apparatuses, and image capturing apparatuses, and relates more specifically to an image processing apparatus that performs control based on a signal obtained from an image sensor provided in an image capturing apparatus, a method for controlling the image processing apparatus, and an image capturing apparatus.
Description of the Related Art
Recently, image sensors have become more and more functional, and improvement in the number of pixels and the frame rate and the like has been achieved. Also, a method for obtaining vector data (optical flow), which indicates movement of an object between a plurality of images, using a signal obtained from an image sensor is known. Moreover, a technique for combining a plurality of images and detecting a moving object based on the optical flow is known. Note that, as a method for obtaining the optical flow, the method disclosed in “Digital Image Processing”, Computer Graphic Arts Society, pp. 243 to 245 is available.
Meanwhile, time-series signal prediction through signal processing and a control method based on prediction have also been proposed. Japanese Patent Laid-Open No. 2013-118450 discloses a signal processing method with which a signal at the time of occurrence of an abnormal value is generated by a prediction device in a system where the abnormal value occurs for a certain time period in an observation signal.
Japanese Patent Laid-Open No. 11-194377 proposes a system for performing image stabilization by locally performing linear approximation based on a value obtained by camera shake detection. Japanese Patent Laid-Open No. 2010-41245 discloses a method for detecting a shake in a focusing direction, and predicting and controlling a shake that is to occur from when an exposure start instruction is given until exposure is started.
However, with Japanese Patent Laid-Open No. 2013-118450, which relates to a technique for predicting a future signal from a current observation signal, a delay that has already occurred in a current observation signal cannot be compensated.
In Japanese Patent Laid-Open No. 11-194377 and Japanese Patent Laid-Open No. 2010-41245, it is assumed that a so-called camera shake is detected using some kind of sensor, but a signal obtained after performing image stabilization is not observed. Since a signal from an image sensor is suitable for detection of the status of an optical system, in the case of adjusting the optical system before exposure, use of the signal from the image sensor enables only the remaining shake after the stabilization to be observed. However, the methods described in Japanese Patent Laid-Open No. 11-194377 and Japanese Patent Laid-Open No. 2010-41245 cannot be applied to this kind of system.